Updated 10:59 pm, Wednesday, July 2, 2014

Cal Fire was battling a wildfire in Northern Napa County near St. Helena. (7/1/14)

Media: San Francisco Chronicle

Nearly 1,000 firefighters slowed the advance Wednesday of a massive blaze that spilled across nearly 6 square miles north of Napa Valley's famed wineries, burning nine structures, including two homes, and threatening nearly 400 others.

But the explosive spread of the Butts Fire, which broke out Tuesday in rugged terrain west of Lake Berryessa, underscored widespread concern that the dry winter has the potential to fuel one of the worst fire seasons in decades.

With rainfall at near-historic lows over the past 12 months - on the heels of two previous years with little precipitation - the forests and grassland of Northern California are exceptionally parched.

"No one can really remember it being drier than this," said Bill Stewart, a forestry specialist at UC Berkeley. "We're like two months drier than usual. This is like September, when everything is nearly bone-dry."

Amid the smoky haze that engulfed northern Napa County, hundreds of residents fled from rural Pope Valley not knowing what would become of their homes and community - and in some cases their pets and livestock.

Brush burns out of control along Butts Canyon Road near Aetna Springs, Calif. on Wednesday, July 2, 2014. The Butts Fire has burned over 3,200 acres of mostly rugged terrain and destroyed as many as five buildings. less

Brush burns out of control along Butts Canyon Road near Aetna Springs, Calif. on Wednesday, July 2, 2014. The Butts Fire has burned over 3,200 acres of mostly rugged terrain and destroyed as many as five ... more

A Cal Fire air tanker drops flame retardant ahead of the fire line near Aetna Springs, Calif. on Wednesday, July 2, 2014. The Butts Fire has burned over 3,200 acres of mostly rugged terrain and destroyed as many as five buildings. less

A Cal Fire air tanker drops flame retardant ahead of the fire line near Aetna Springs, Calif. on Wednesday, July 2, 2014. The Butts Fire has burned over 3,200 acres of mostly rugged terrain and destroyed as ... more

A Department of Corrections hand crew mobilizes to cut a containment line off of Butts Canyon Road near Middletown, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through 3,200 acres of mostly rugged terrain and destroyed as many as five buildings. less

A Department of Corrections hand crew mobilizes to cut a containment line off of Butts Canyon Road near Middletown, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through ... more

Kelseyville firefighters prepare to pull back from the fire on Butts Canyon Road, as the fire jumps the road, Tuesday July, 1, 2014, outside Middletown, Calif., at the border between Lake and Napa counties. By early evening 140 homes were evacuated and 2,500 acres were burned. less

Kelseyville firefighters prepare to pull back from the fire on Butts Canyon Road, as the fire jumps the road, Tuesday July, 1, 2014, outside Middletown, Calif., at the border between Lake and Napa counties. By ... more

Not much is left of a shed off of Butts Canyon Road near Middletown, Calif. on Wednesday, July 2, 2014, after flames roared through the area Tuesday night. As of Wednesday morning, the Butts Fire has burned through 3,200 acres of mostly rugged terrain and destroyed as many as five buildings. less

Not much is left of a shed off of Butts Canyon Road near Middletown, Calif. on Wednesday, July 2, 2014, after flames roared through the area Tuesday night. As of Wednesday morning, the Butts Fire has burned ... more

Cheryl Brown comforts her dog Dutch at Middletown High School in Middletown, Calif. on Wednesday, July 2, 2014, after fleeing her Berryessa Estates home. As of Wednesday morning, the Butts Fire has burned through 3,200 acres of mostly rugged terrain and destroyed as many as five buildings. less

Cheryl Brown comforts her dog Dutch at Middletown High School in Middletown, Calif. on Wednesday, July 2, 2014, after fleeing her Berryessa Estates home. As of Wednesday morning, the Butts Fire has burned ... more

A destroyed shed is seen off Butts Canyon Road near Middletown, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through 3,200 acres of mostly rugged terrain and destroyed as many as five buildings. less

A destroyed shed is seen off Butts Canyon Road near Middletown, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through 3,200 acres of mostly rugged terrain and destroyed ... more

Not much is left of a shed off of Butts Canyon Road near Middletown, Calif. on Wednesday, July 2, 2014, after flames roared through the area Tuesday night. As of Wednesday morning, the Butts Fire has burned through 3,200 acres of mostly rugged terrain and destroyed as many as five buildings. less

Not much is left of a shed off of Butts Canyon Road near Middletown, Calif. on Wednesday, July 2, 2014, after flames roared through the area Tuesday night. As of Wednesday morning, the Butts Fire has burned ... more

Fire crews from Marin County on Snell Valley Road near Berryessa Estates, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through 3,200 acres of mostly rugged terrain and destroyed as many as five buildings. less

Fire crews from Marin County on Snell Valley Road near Berryessa Estates, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through 3,200 acres of mostly rugged terrain and ... more

Smoke rises from the Butts Canyon Fire on Tuesday July 1, 2014, near Middletown, Calif., on the border between Lake and Napa counties. Crews are battling a raging wildfire that has burned more than 2,500 acres, damaged five structures and prompted mandatory evacuations. less

Smoke rises from the Butts Canyon Fire on Tuesday July 1, 2014, near Middletown, Calif., on the border between Lake and Napa counties. Crews are battling a raging wildfire that has burned more than 2,500 acres, ... more

Cheryl Brown checks on her cats at Middletown High School in Middletown, Calif. on Wednesday, July 2, 2014, after fleeing her Berryessa Estates home. As of Wednesday morning, the Butts Fire has burned through 3,200 acres of mostly rugged terrain and destroyed as many as five buildings. less

Cheryl Brown checks on her cats at Middletown High School in Middletown, Calif. on Wednesday, July 2, 2014, after fleeing her Berryessa Estates home. As of Wednesday morning, the Butts Fire has burned through ... more

Beth Huckins and her dog Lucas wait out the fire at the Middletown High School evacuation center in Middletown, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through 3,200 acres of mostly rugged terrain and destroyed as many as five buildings. less

Beth Huckins and her dog Lucas wait out the fire at the Middletown High School evacuation center in Middletown, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through ... more

Cal Fire crews wait to be deployed on Butts Canyon Road near Middletown, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through 3,200 acres of mostly rugged terrain and destroyed as many as five buildings. less

Cal Fire crews wait to be deployed on Butts Canyon Road near Middletown, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through 3,200 acres of mostly rugged terrain and ... more

A PG&E crew climbs a charred hillside to assess downed power lines off of Butts Canyon Road near Middletown, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through 3,200 acres of mostly rugged terrain and destroyed as many as five buildings. less

A PG&E crew climbs a charred hillside to assess downed power lines off of Butts Canyon Road near Middletown, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through ... more

A Smokey Bear sign warns of extreme fire danger on Snell Valley Road near Berryessa Estates, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through 3,200 acres of mostly rugged terrain and destroyed as many as five buildings. less

A Smokey Bear sign warns of extreme fire danger on Snell Valley Road near Berryessa Estates, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through 3,200 acres of mostly ... more

A volunteers checks on Lou Leet at the evacuation center at Middletown High School in Middletown, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through 3,200 acres of mostly rugged terrain and destroyed as many as five buildings. less

A volunteers checks on Lou Leet at the evacuation center at Middletown High School in Middletown, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through 3,200 acres of ... more

A plastic kayak appears undamaged off of Butts Canyon Road near Middletown, Calif. on Wednesday, July 2, 2014 after flames roared through during the night. As of Wednesday morning, the Butts Fire has burned through 3,200 acres of mostly rugged terrain and destroyed as many as five buildings. less

A plastic kayak appears undamaged off of Butts Canyon Road near Middletown, Calif. on Wednesday, July 2, 2014 after flames roared through during the night. As of Wednesday morning, the Butts Fire has burned ... more

A Department of Corrections hand crew cuts a containment line off of Butts Canyon Road near Middletown, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through 3,200 acres of mostly rugged terrain and destroyed as many as five buildings. less

A Department of Corrections hand crew cuts a containment line off of Butts Canyon Road near Middletown, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through 3,200 acres ... more

Cal Fire crews wait to be deployed on Butts Canyon Road near Middletown, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through 3,200 acres of mostly rugged terrain and destroyed as many as five buildings. less

Cal Fire crews wait to be deployed on Butts Canyon Road near Middletown, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through 3,200 acres of mostly rugged terrain and ... more

A Cal Fire supervisor directs a Department of Corrections hand crew cutting a containment line near Middletown, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through 3,200 acres of mostly rugged terrain and destroyed as many as five buildings. less

A Cal Fire supervisor directs a Department of Corrections hand crew cutting a containment line near Middletown, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through ... more

A Department of Corrections hand crew cuts a containment line off of Butts Canyon Road near Middletown, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through 3,200 acres of mostly rugged terrain and destroyed as many as five buildings. less

A Department of Corrections hand crew cuts a containment line off of Butts Canyon Road near Middletown, Calif. on Wednesday, July 2, 2014. As of Wednesday morning, the Butts Fire has burned through 3,200 acres ... more

A crew heads back downhill as flames advance up a hillside on the Butts Canyon Fire, Tuesday, July 1, 2014, outside Middletown, Calif., on the border between Lake and Napa counties. By early evening 140 homes were evacuated and 2,500 acres were burned. less

A crew heads back downhill as flames advance up a hillside on the Butts Canyon Fire, Tuesday, July 1, 2014, outside Middletown, Calif., on the border between Lake and Napa counties. By early evening 140 homes ... more

Photo: Kent Porter, Associated Press

Image 28 of 34

The Cal Fire helitack crew from Boggs Mountain puts out flames around a Cal Fire dozer transport as the Butts Canyon fire jumps Butts Canyon Road, Tuesday, July 1, 2014 . outside Middletown, Calif., near the border between Napa and Lake counties. By early evening 140 homes were evacuated and 2,500 acres were burned. less

A Cal Fire helicopter makes a drop on the Butts Canyon Fire on Tuesday, July 1, 2014, near Middletown, Calif., close to the border between Lake and Napa counties. By early evening 140 homes were evacuated and 2,500 acres were burned. less

A Cal Fire helicopter makes a drop on the Butts Canyon Fire on Tuesday, July 1, 2014, near Middletown, Calif., close to the border between Lake and Napa counties. By early evening 140 homes were evacuated and ... more

A Napa County fire crew douses flames near Aetna Springs, Calif. on Wednesday, July 2, 2014. The Butts Fire has burned over 3,200 acres of mostly rugged terrain and destroyed as many as five buildings.

A Napa County fire crew douses flames near Aetna Springs, Calif. on Wednesday, July 2, 2014. The Butts Fire has burned over 3,200 acres of mostly rugged terrain and destroyed as many as five buildings.

Fire personnel pull back from a wall of flames as it jumps Butts Canyon Road and Snell Valley Road, Tuesday, July 1, 2014, outside Middletown, Calif., near the border between Lake and Napa counties. By early evening 140 homes were evacuated and 2,500 acres were burned. less

Fire personnel pull back from a wall of flames as it jumps Butts Canyon Road and Snell Valley Road, Tuesday, July 1, 2014, outside Middletown, Calif., near the border between Lake and Napa counties. By early ... more

"It's terrible trying to think what to take," said Beth Huckins, 54, who left the area with her husband, son, dog and a cat - but without the family's second feline. "I didn't know how much time I had."

She was alongside dozens who slept in cots outside the high school in Middletown (Lake County), where one of two evacuation centers had been set up for the displaced.

They could only watch while the golden hills of northern Napa and southern Lake counties darkened as flames charred ridgelines, scorched power lines and smothered trees.

Many more fires

Already this year, more wildfires have hit the state than usual. State firefighters, who battle the bulk of California's blazes, have counted 2,700 incidents between January and July - a 50 percent jump from the 1,800 wildland fires they respond to on average during the same period, according to state fire data.

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Last month, an unusually early 2,600-acre blaze raged west of Kern County's Lake Isabella in the southern Sierra. In May, a series of conflagrations in San Diego County tore through some 14,000 acres, forcing more than 20,000 people to evacuate.

Normally, the fire season isn't in high gear until at least July.

In the Bay Area, 350 mostly small fires have burned this year. That compares to 225 on average during the same months, according to state data.

The Butts Fire, which grew to thousands of acres in a matter of hours, demonstrates just how much of a danger California's drought presents, fire experts said.

"This week's (hot) weather was not the factor that pushed this fire," said Daniel Berlant, a spokesman for the state Department of Forestry and Fire Protection, noting that temperatures in the Napa County hills were relatively mild, and winds light, when the fire started early Tuesday afternoon.

What made the fire take off, Berlant explained, was the lack of moisture in the vegetation, making for prime burning material.

Fire experts said the parts of the greater Bay Area that don't get much fog, such as the Wine Country, will be most vulnerable to fire this year.

More fighting fires

State firefighters said they're ready for the heightened threat. Cal Fire brought on 2,700 seasonal firefighters earlier than usual, in the spring instead of the summer, and has about 300 more than last year - a bump funded by state emergency drought funds.

In January, Gov. Jerry Brown declared a drought emergency in California, pledging to provide the money needed to combat what was expected to be a tough year on the fire lines. With seasonal workers, year-round employees and inmate crews, the state's firefighting force stands at about 12,000.

Berlant said the elevated staffing has paid off. Though the agency has responded to more blazes in the first half of the year, the size of those fires stands at about 13,000 acres - 3,000 less than the average for the period.

By Wednesday afternoon, the nearly 1,000 firefighters who had descended upon the Butts Fire were attacking it from land and from the sky, with helicopters and several fixed-wing aircraft dropping water and fire retardant.

The flames had pushed from their origin in Pope Valley north to Lake County's Snell Peak, burning 3,800 acres. Of the two homes that caught fire, one was destroyed and the other damaged, officials said.

30 percent contained

Authorities estimated that the fire was 30 percent contained, but they expected to update that figure late Wednesday.

Pope Valley resident Lou Leet, 57, said she was at work in southern Napa County on Tuesday when she got the call that her home was in harm's way.

"I just high-tailed it up there, but I couldn't get in," said Leet, who also slept in the parking lot of Middletown High School. "I still have cats up there. I'm very anxious to see if they're OK."

Gary Stanley, 58, decided not to leave his home on Butts Canyon Road, even though fire officials were recommending evacuations.

"It was scary last night," he said Wednesday. "We spent six hours watching 300-foot flames."

Stanley was running low on fuel for his generator, so he thought he might have to eventually abandon his property.

The cause of the Butts Fire remains under investigation. The blaze is believed to have started near Butts Canyon and James Creek roads shortly after noon Tuesday.

Mandatory evacuations remained in effect late Wednesday along Butts Canyon Road as well as in the Berryessa Estates area. No injuries had been reported.

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